As one of piezoelectric resonator devices, a tuning-fork type crystal resonator is known that employs a tuning-fork type crystal resonator plate including a base portion and a vibrating portion that has two leg portions protruding from the base portion (see, for example, Patent Document 1).
In such a tuning-fork type crystal resonator plate, a bonding portion that is bonded to the outside is formed protruding from an end face opposite the other end face of the base portion in which the two leg portions are formed. The bonding portion formed protruding from the end face of the base portion is shaped to extend therefrom and branch into two directions toward both sides, forming a T shape, and the distal end portions of the bonding portion extend in the same direction as the distal end portions of the two leg portions.
The main body casing of the tuning-fork type crystal resonator is made up of a base and a lid. Inside the main body casing, the distal end portions of the bonding portion of the tuning-fork type crystal resonator plate are electromechanically bonded to the base with a conductive material, and the bonded tuning-fork type crystal resonator plate is hermetically sealed inside the main body casing. With the tuning-fork type crystal resonator, vibration leak (acoustic leak) can be prevented.